Effect of Air Pollution on Professional Baseball Umpires

Professional baseball umpires are not supposed to make errors, yet they sometimes do.  That happens more often on days when the air is badly polluted, suggests a new scientific study.

If umpires make more bad decisions on bad-air days, then maybe so does anyone who has to make rapid judgment calls. As the saying goes: more research is needed.

The study is: “Air Quality and Error Quantity: Pollution and Performance in a High-Skilled, Quality-Focused Occupation,” James Archsmith, Anthony Heyes, and Soodeh Saberian, Journal of the Association of Environmental and Resource Economists, vol. 5, no. 4, October 2018. (Thanks to Tom Gill for bringing this to our attention.)

The authors, at the University of Maryland and the University of Ottowa, explain: “We provide the first evidence that short-term exposure to air pollution affects the work performance of a group of highly skilled, quality-focused employees. We repeatedly observe the decision making of individual professional baseball umpires, quasi-randomly assigned to varying air quality across time and space. Unique characteristics of this setting combined with high-frequency data disentangle effects of multiple pollutants and identify previously underexplored acute effects. We find that a 1 ppm increase in 3-hour CO causes an 11.5% increase in the propensity of umpires to make incorrect calls and a 10 mg/m3 increase in 12-hour PM2.5 causes a 2.6% increase.”

Anyone who reads the paper carefully will notice that there is a Trick. Specifically, the paper cites a study done by Michael A. Trick and colleagues: “Scheduling major league baseball umpires and the traveling umpire problem,” Michael A. Trick, Hakan Yildiz, and Tallys Yunes, Interfaces, vol. 42, no. 3, 2001, pp. 232–44.

Neither of those papers delves much into the related question of dust. Here’s a short video showing an umpire having to deal with a small, sudden uptick of airborne dust:

UPDATE (distantly related, sort of): Major League Baseball “players who sustained a concussion lost a mean of US$654,990 annually compared with players who took nonmedical leave.” That’s the word in a just-now-published study called “Short-Term Outcomes of Concussions in Major League Baseball: A Historical Cohort Study of Return to Play, Performance, Longevity, and Financial Impact.” (Thanks to Ivan Oransky for bringing this to our attention.)